.vertical {
  display: flex;
  flex-direction: column;
}

.horizontal {
  display: flex;
}

.mark {
  width: 100%;
  height: 650px;
  background: rgba(0, 0, 0, .5);
}

.box {
  position: absolute;
  background: #fff;
  top: 200px;
  left: 130px;
  width: 150px;
  height: 150px;
}